USB printer cable VS USB audiophile grade cable?


I have converted to PC audio about 2 years ago and enjoying the hobby. I recently upgraded my DAC from a Benchmark DAC1 HDR to a DAC2 HGC mainly to download DSD files. I am now using a 'regular' 12 ft. Belden USB printer cable purchased at Office Depot which sounds great. The Benchmark uses asynchronous clocking system to re-clock incoming bytes from the PC.

I just purchased an audiophile grade USB cable (Furutech GT2 Pro-USB). To my great surprise, this Furutech cable just trounced the printer cable. Noise level is down, music micro-details are popping up and bass goes down much lower. I've listened to some of my older CD's which I am pretty familiar with and hearing details I never heard previously. So it has nothing to do with jitter, since the Benchmark is handling it. The 'bits are bits' theory, which I subscribed to has some cracks to it...

Before I purchased this cable, I was of the opinion that the only sonical gain I would get would be better immunity to EMI/RFI since the Furutech has greater isolation. However, this purchase turned out to be of much greater sonical value for about $300.

I am perplexed and very happy at the same time :-)

What is going on?
dasign
Yes I agree the USB cable makes a difference. I bought an Audioquest Diamond USB a while back to replace a ridge street audio cord and the Audioquest cable tuned things in just that much more to my liking. I wouldn't call it night and day difference but certainly one that I didn't want to give up either. I have another DAC I use in a recording studio situation and that uses Firewire and I've been thinking of trying the Diamond Firewire cable for that and see what improvements that can bring me.
When it comes to playing back digital music files, everything matters. If you
have a system resolving enough to re-create the natural micro-details that
convey musicality, you will easily hear the difference between standard
USB data cables and well-designed audiophile grade cables. The best I
have heard so far are the brand new versions of Shunyata's Venom USB
and the Chord Company's Signature Tuned Array USB. They both get
much closer to S/PDIF and AES/EBU performance than any stock USB I
have ever tried. Both companies' websites do a decent job of explaining
their approaches to this interface.
While I haven't tried different audio grade USB cables, their impact on sound is well documented by users on other fora. exaSound might be the exception and their DACs indeed neutralize what is going on upstream - be it at the computer or the cable - by using a buffer inside the DAC from where data is retrieved exactly at the DAC's clock pace.
Lewinskih01,

True for synchronous older DACs, better USB cable will not contribute to additional jitter from incoming PC. However, the majority of newer DACs like Benchmark DAC2 HGC and probably exaSound which you mentionned, use asynchronous clocking device which get rid of jitter from incoming PC. The audio impact of USB cables is not well that documented IMHO, for these asynchronous DACs which are more recent. The majority of USB cable reviews that I've seen in audio trade magazines are 2-3 years old, and performed on sychronous DACs variety.

So I am suggesting that jitter is not part of the equation here when using asynchronous DACs. The audiophile variety of USB cables are doing something rigth to the incoming streaming data, but at which level exactly?

The audio improvement is very noticeable, very similar to replacing a middle range to top of the line interconnect from same manufacturer line.

Any suggestions?
There are a number of possible explanations that occur to me:

1)Electrical noise that may be transmitted from the computer to the DAC via the cable could to some degree couple "around" the DAC's buffer memory and jitter rejection circuitry (via grounds, stray capacitances in the circuits, etc.), and thereby affect jitter at the point of D/A conversion. The bandwidth and impedance characteristics of the cable will affect the amount and the frequency content of that noise.

2)Some of that noise may result from groundloop effects between the computer and the DAC, which in turn will be affected by the resistance and inductance of the ground conductor within the cable.

3)USB signals have substantial content at RF frequencies. The quality and characteristics of the shielding in different cables may result in differences in radiation of electrical noise from the cable into unrelated parts of the system (including cables and power cords as well as components), which may be sensitive to that noise to varying degrees at various frequencies. The sonic consequences of that can be expected to be arbitrary and unpredictable. The fact that your cable, or at least the previous Belden cable, is or was 12 feet long perhaps increases the likelihood of those effects.

4)Earlier Benchmark DAC's employed an Asynchronous Sample Rate Conversion (ASRC) approach to jitter reduction, which I understand is a technology that is not always 100% bit perfect when faced with significant amounts of jitter on the incoming signal. I suspect that is not applicable to the more recent DAC2 HGC model you are using, but perhaps it too is not 100% bit perfect under some circumstances?

I would add, however, that IMO none of this necessarily suggests that a high degree of correlation between performance and price should be expected among the various audiophile-oriented cables that are available. It also does not suggest any reason to expect a high degree of consistency between the sonic results provided by a given upgraded cable when used in different systems.

Regards,
-- Al
Hi Al,

I think we are getting somewhere. The overall resistance of the individual cables composing the Furutech USB should far less than the printer cable which are probably run of the mill copper cables with high impurity levels.

The Furutech cables are silver plated OCC conductors for minimal resistance and connectors are 24K gold plated. They also have 3 layer shield construction. They aslo use special damping and isolation materials for best frequency extension and tonal balance.

I'm with you on the pricing aspect of the audiophile grade USB cable pricing. For me, manufacturing a decent USB data cable is somewhat less challenging than building a good quality XLR interconect cable in the analog domain. While I have invested some decent money on my XLR interconnects ($2K), I was not ready to put more than a few hundred bucks on an audiophile grade USB.

I've been using Furutech products (wall plates, connectors, cable,etc.) for a few years with great satisfaction and was surprisingly pleased with my recent USB cable purchase.

Digital audio was less than perfect when it started in the 80's but have come along way since then. It is so convenient to change CDs directly from my seat using Jriver's JRemote. Cymbals are just starting to sound rigth :-)
Al,

Excellent post!

There certainly is *not* a direct correlation between price and performance
and I also concur that USB cables may not produce the same results from
system to system. That said, there are a few well-designed USB cables out
there that mange to intelligently address some of the challenges you cite
and, as a rule, these cables perform better than stock USB cables and
more consistently so when it comes to delivering music files.

Nonetheless, the wide variety of computer systems and the noise they
create does pose a significant challenge to designers of the USB interface.
for me furutech did not work out,it just sounded exaggerated,enhanced bass, recessed midrange,fatiguing highs.Printer cable really had variuos noise issues.I made usb cable from flat red copper "tasker" cable.And it works fine
Extravaganza,

Excuse my question, since English is not my first language, but what is a red flat tasker cable? Where can you purchase such cable? What is the dielectric used in your cable and which USB connector brand did you use to build your cable? Just curious...
tasker
Cable company from Italy.I bought from diy shop this cable and connectors
Very interesting conversation. Not completely on topic but related, i have been confused as to why i have found better results using usb vs optical cables to connect my macbook to my rega dac. I would think that bits would arrive cleaner by having a sort of wall between the noisy multi purpose computer and the dac. Optical i would have thought would provide this vs a usb which relies on an electric signal from the computer. These improved results were noticable with none of steves suggestions and a cheap printer cable.
I would think that bits would arrive cleaner by having a sort of wall between the noisy multi purpose computer and the dac. Optical i would have thought would provide this vs a usb which relies on an electric signal from the computer.
Yes, that is a potential advantage of an optical connection. However what you have found, at least in your setup, is that the potential disadvantages of an optical connection outweigh that potential advantage.

One potential disadvantage, I believe, is that the electrical outputs of optical-to-electrical transducers tend to have slow risetimes and falltimes (i.e., slow transitions between their higher voltage and lower voltage states, and vice versa), which can adversely affect the jitter performance of the subsequent circuitry in the DAC. Also, my understanding is that waveform quality, and ultimately jitter, can often be adversely affected by the quality, or lack thereof, of many optical cables.

It is telling that in S/PDIF applications, where digital signals are conveyed from a transport to a DAC, coax connections seem to be preferred by most audiophiles to optical connections.

Regards,
-- Al

Better shielding against noise sources almost always pays dividends when needed. No doubt about that.
It's caused by dirty USB power. It actually adds signal to your music. The Furutech cable is well engineered and rejects some of this electromagnetic interference, which is from your computer. Think about it, there are millions of circuits inside your computer and as they operate they cause interference on a quantum level. It does not affect the computer at all, and the noise generated by these effects simply flows with the electricity, no big deal. Now, if you connect your USB cable to your USB DAC then that polluted power can freely flow down the 5 volt power feed, aka V bus, along the powerline inside each USB cable. This extra noise pollutes the analog outputs of your DAC. It goes right through and into your speakers. Your observation totally nailed it.

USB Disruptor solves this problem, you can read more on usbdisruptor dot com - for $49, not hundreds or thousands.

And, even if your DAC reclocks it doesn't matter. I've gotten great sound out of cheap DAC's - no asynch or fancy Sabre chips - simply by removing the dirty usb power. USB Disruptor makes virtually any DAC sound great, and I don't mean it makes any DAC sound like a Bricasti M1, or DirectStream DAC, or any other of the world's finest DACs, what I mean is it lets the DAC do what it's designed to do, and the cheapest DAC's don't sound bad, they just sound a bit hollow, but very musical and enjoyable.

I assure you, no DAC sounds good with dirty USB power, and like you Dasign, you've heard the difference, but there are so many other people out there that are missing out.

And you don't have to spend a lot, this is a simple problem that was not well understood and in some ways overlooked.

Dirty USB power is the cause of digital woes, I will go down as saying that forever because I've heard it first hand.
It's caused by dirty USB power. It actually adds signal to your music. The Furutech cable is well engineered and rejects some of this electromagnetic interference, which is from your computer. Think about it, there are millions of circuits inside your computer and as they operate they cause interference on a quantum level. It does not affect the computer at all, and the noise generated by these effects simply flows with the electricity, no big deal. Now, if you connect your USB cable to your USB DAC then that polluted power can freely flow down the 5 volt power feed, aka V bus, along the powerline inside each USB cable. This extra noise pollutes the analog outputs of your DAC. It goes right through and into your speakers. Your observation totally nailed it.

USB Disruptor solves this problem, you can read more on usbdisruptor dot com - for $49, not hundreds or thousands. It's for sale on Audiogon.

And, even if your DAC reclocks it doesn't matter. I've gotten great sound out of cheap DAC's - no asynch or fancy Sabre chips - simply by removing the dirty usb power. USB Disruptor makes virtually any DAC sound great, and I don't mean it makes any DAC sound like a Bricasti M1, or DirectStream DAC, or any other of the world's finest DACs, what I mean is it lets the DAC do what it's designed to do, and the cheapest DAC's don't sound bad, they just sound a bit hollow, but very musical and enjoyable.

I assure you, no DAC sounds good with dirty USB power, and like you Dasign, you've heard the difference, but there are so many other people out there that are missing out.

And you don't have to spend a lot, this is a simple problem that was not well understood and in some ways overlooked.

Dirty USB power is the cause of digital woes, I will go down as saying that forever because I've heard it first hand.
Check out the USB Disruptor thread on Computer Audiophile. The seller has been asked over and over, in a reasonable manner, to come up with something, anything, other than his subjective beliefs, that backs up his theory of "dirty power", and how his USB Disruptor product solves the problem.

So far, nothing.
Better USB cables seem to have several attributes:

1 better shielding
2 heavier ground and power wires
3 better dielectrics
4 smaller signal wires
5 good impedance match

USB uses a differential signalling technique.. This inherently implies some common-mode noise rejection at the receiver. The problem is that these receivers dont reject CM noise vey well.

Some async USB interfaces use the power in the cable to generate the timing/clocking and therefore, any variation in this voltage can cause jitter. The voltage from a PC USB port is not that clean to begin with,so the cable just adds inductance, which adds noise. This is the reason why heavier power and ground wires improve things.. The best scenerio of course is to use an external high quality supply and not the one from the computer.

Improving the common-mode noise will also reduce jitter.. There are two ways to accomplish this:

Add a CM filter to the cable
Get a USB interface withgalvanic isolation

Better Sheilding of the cable can also have an effect, but I’m not sure why.  There may be RFI to the receiver or impact on the impedance.

Steve N.
Empirical Audio

AQ Diamond is great. My A/B testing confirmed this.
Good cable, but TotalDAC cable beats AQ Diamond.
Good cable, but TotalDAC cable beats AQ Diamond.
That goes to show that sound is system dependent.  My findings are identical to rgs92, Audio Quest Diamond USB is the best I’ve heard.

I had several other brands including TotalDAC.   TotalDAC was darker and smaller sound stage than AQ Diamond.


dasign, and others. You should try the Curious usb cables. Most impressive! Perhaps a little pricey, but well worth it.

Here's a link if your interested.

http://www.curiouscables.com/